The poet and critic Derek Stanford, who has died aged 90, had reasons to be grateful to the novelist Muriel Spark, his one-time lover, but her characterisation of him as the fifth-rate, pushy writer Hector Bartlett in A Far Cry from Kensington (1988) was not among them. Nor were her pronouncements on his 1963 work, Muriel Spark: A Biographical and Critical Study. "If Mr Stanford had applied to me," she wrote, "I would have advised against this undertaking."

But, 50 years after they parted, his poems seemingly inspired by the affair appeared in the Times Literary Supplement (TLS) for several years, conjuring up too the doomed 1890s poets he identified with and championed.

Born in Lampton, Middlesex, Stanford was educated at the Latymer upper school, Hammersmith, west London, after which his father compelled him into a lawyer's office. During the second world war, as a concientious objector, he served in the Non-Combatant Corps. In 1946 he emerged in print with his lifelong friend the poet John Bayliss in a two-hander volume, A Romantic Miscellany. His solo debut, Music for Statues (1948), was praised in the TLS. Many critics over the years agreed with this view. Geoffrey Grigson promoted him in Poetry of the Present (1949). Later, The Traveller Hears the Strange Machine: New and Selected Poems 1946-79 (1980) was praised by the poet Robert Nye - "a few dozen lines likely to survive ... as long as English poetry is read."

Spark entered Stanford's life in the late 1940s when he asked for work at the Poetry Society, where she was secretary and ran the Poetry Review. When she was ousted soon afterwards, he organised a protest reading, and then petitioned TS Eliot and Graham Greene for money on her behalf when she collapsed after using the appetite suppressant Dexedrine. Spark's autobiography Curriculum Vitae (1992) later claimed that her literary success made Stanford ill, but then, his success on her behalf made her well.

Stanford's The Freedom of Poetry (1947) was the first thorough critique of the 1940s, and a trendsetter. Well-received, his John Betjeman: A Study (1961), the first-ever monograph on Betjeman, was denounced by the author. His collaborations with Spark focused on Romantic poets, but Stanford's own criticism started impressively with a 1951 appreciation of Christopher Fry, whom he had met in the corps, and moved on to Eliot, the poets of the 1930s, and Dylan Thomas. He focused on the 1890s, and the condemned playground of 1940s Soho, for the rest of his career.

He produced Aubrey Beardsley's Erotic Universe in 1967, while he was teaching at North Foreland girls' school in Hampshire (1962-68) and the City Literary Institute in London. Stanford once described himself as "a sceptical, sprightly Cavalier". Such sympathies invoke those mainly Catholic converts he caused to be reappraised, who included the alcoholic Lionel Johnson and the tubercular Ernest Dowson. But the multi-tasking, longlived 1890s critic Arthur Symons is the writer Stanford deserves to be measured against. These studies of the fin de siècle, along with his memoir Inside the Forties (1977) - deftly respectful to and gossipy about Spark - are his best-remembered prose.

Stanford exhibited a technophobia which extended to cars and typewriters. He found happiness with two wives, both poets, who both typed to dictation. The first, Margaret Holdsworth, wrote as Margaret Philips. After her death, he married Julie Whitby, who survives him.

• Derek Stanford, poet and critic, born 11 October 1918; died 19 December 2008